Electric utility meters comprise a circular cylindrical base portion containing a high power socket and include an annular flange. An electric meter operating mechanism is enclosed in a circular cylindrical glass housing and includes mating socket blades for insertion into the socket of the base portion. The glass enclosed meter mechanism includes a circular flange which abuts the flange of the socket base portion, the flanges being clamped together with a circular clamping ring.
To preclude access to the meter and theft of electrical service, it is typical to provide locks and sealing mechanisms for sealing the clamping ring to indicate tampering and opening of the meter. The clamping ring comprises a circular channel shaped member having spaced ends which are resilient relative to one another in the plane of the ring. Flanges extend from these facing ends and are typically secured together by a variety of different locking mechanisms to secure the glass meter housing to the socket base.
In one embodiment a hole is provided in each of the mating flange portions at the extended ends of the ring and a locking device is inserted in the mating aligned holes to lock these elements together. Such a locking device is sometimes referred to as a barrel lock. A barrel lock may comprise a cylindrical element including a female member for receiving the cylindrical element. The cylindrical element has expansible balls which are expanded or retracted by a key mechanism. The barrel when inserted in the female member locks the two ring ends together. An additional aperture may be formed in the barrel lock for receiving a seal for further providing tamper evidence. This device requires what is referred to as a key. The key is a spring-loaded device inserted in the barrel lock for locking and unlocking the barrel lock. See for example, U.S. Pat. Nos. 4,446,603, 4,063,434, 4,008,535 and 4,049,313.
In a further embodiment of an apparatus for locking utility meters, the meter is enclosed in a steel box and the box is then in turn locked in place with a locking mechanism. This also uses a barrel lock and key. For example, U.S. Pat. No. 4,144,729 discloses an electric meter box lock. Of interest is co-pending application entitled Box lock Construction filed on Mar. 8, 1993, Ser. No. 08,027,385 now U.S. Pat. No. 5,315,849 and assigned to the assignee of the present invention and filed in the name of George Georgopoulos. This latter application also discloses an electric meter box lock device.
However, the electric meter box lock arrangement is relatively costly in that it requires a steel box with a hinged cover and a relatively costly lock mechanism for receiving a key-operated barrel lock of the type described above. This locking arrangement therefore is not desirable for use on every electric utility meter, because of the large number of such meters that are or may be installed. Further, it is recognized that a large number of utility customers are not prone to tamper with or steal electric service. Therefore, a relatively low cost locking device is recognized by the present inventors as most desirable for use with such widely available meters.
However, it is also recognized that in certain regions theft of service from the electrical meters is more likely to occur and more secure locking arrangements are required. However, it is not, as recognized by the present inventors, as desirable to provide a relatively high cost complex high security locking mechanisms on every meter even in these latter regions. That is because as is recognized not all customers in these regions are likely to steal electrical service although a higher percentage of such customers than in other regions may be prone to do so. Further, it is also recognized that when certain customers are confronted with the fact that they did in fact tamper with their electric meter service, that having been once caught as such an act, such customers will rarely attempt to steal service again. There is also recognized that some customers find it a challenge to open such security devices for electric utility meters and will repetitively attempt to break into such meters. With such repetitive action the present inventors recognize a need for a progressively increasingly more secure utility meter locking arrangement, which more secure arrangements are more costly as the level of security increase. Therefore, not only is the configuration of the locking devices changed from meter-to-meter in accordance with the frequency of occurrence of theft attempts from that meter, but as the locking security level increases, so does the cost.